It is possible to manufacture miniature hole plates, membrane filters, weir filters, and similar structures by means of semiconductor manufacturing-based processes, such as lithography and etching. These miniature structures or elements may be used as fluid filters, for example.
For the manufacturing of membrane filters from thin semiconductor or glass wafers, e.g., from Si (silicon) wafers for e.g. MEMS applications (MEMS: micro electro-mechanical system), the structuring of the filter membrane may be done by, for example, wet chemical etching or dry etching before or after the filter separation process. The filter separation process is also known as “dicing” or “singulation”. As the handling of the structured semiconductor filter membrane is somewhat critical and delicate, the separation process may be done by separate dicing techniques (e.g., mechanical dicing, laser dicing, stealth dicing) before or after the structuring of the filter membrane. This separation processes might cause either mechanical damage, e.g., chipping, or amorphization/mechanical stresses of the bulk semiconductor or glass at the filter edges which will deteriorate the mechanical stability of the membrane leading to a significant decrease in their mechanical breaking strength.
Especially when the bulk semiconductor is relatively thin (for example, 100 μm or below), damage-free dicing becomes increasingly difficult. Indeed, the breaking strength typically is a quadratic function of the substrate thickness so that the probability of fracture increases significantly with decreasing thickness.